In your example, 211.9 billion is 131.7% of the 2002 figure, so the
2002 figure is 211.9 / 1.317.

In Excel, if you put 211.9 in cell A1 and 31.7% in cell B1, then in C1
you could have this formula:

=A1/(1+B1)

Hope this helps.

Pete

On Aug 1, 1:52*am, Serena wrote:
I have been working as an Elementary computer teacher. *I was recently
promoted to teaching MS/HS... *I have been busy this summer creating lesson
plans and I have more to learn about Excel & formulas. *I want to teach the
students how to use a particular chart. *I have the top 10 countries that
import from the U.S. *I have the $ amounts for each country. *Canada imported
211.9 billion in 2005, which is up 31.7% from 2002. *What is the formula to
figure out the amount in 2002? *I know that on the news I will hear that a
certain stock is up _______ % from yesterday. *I could forego this, but
believe that this is very important to teach. *Algebra was NOT my strong
suit. *My husband came up with a formula, but neither of us know how to write
it into Excel. *I need to understand it, so that I can teach it. *Your help
is greatly appreciated!
-Serena-